Upper Miocene echinoids from the Yorktown Formation of Virginia and their environmental significance /
Kier, Porter M.
Upper Miocene echinoids from the Yorktown Formation of Virginia and their environmental significance / [by] Porter M. Kier. - Washington : Smithsonian Institution Press; [for sale by the Supt. of Docs., U.S. Govt. Print. Off.] 1972. - 41 p. : ill. ; 26 cm. - Smithsonian contributions to paleobiology ; 13 .
Upper Miocene echinoids from the Yorktown Formation of Virginia and their environmental significance / [by] Porter M. Kier. - Washington : Smithsonian Institution Press; [for sale by the Supt. of Docs., U.S. Govt. Print. Off.] 1972. - 41 p. : ill. ; 26 cm. - Smithsonian contributions to paleobiology ; 13 .